Apparatus for cutting drill-bits.



'PATENTED DEC. 5, 905.

APPLICATION FILED JUNE 15, 1904.

JOSEPH ADOLPH GEORGE UNITED STATES PATENT OFFICE. 'KIRSTEN, OF FORDSBURG, NEAR BURG, TRANSVAAL.

J OHANNES- i No. 806,347.

To all whom it may concern:

Be it known that I, J OSEPH ADOLPH GEORGE KIRSTEN, a subject of the King of England, residing at Fordsburg, near Johannesburg; Transvaal, have invented certain new and useful Improvements in Apparatus for Cutting Drill-Bits and the Like, of which the following is a specification. I

This invention relates to apparatus for cutting that kind of rock-drilling-machine bit known as a "Star bit or for other drills or bits of cruciform section employed either for machine orhand rock-drilling, and is designed to provide an efiicient and comparatively simple and ine'xpensive machine in which the bits or drills may becut expeditiously.

the wings or webs of the drill or bit when necessary. The invention will now be described by aid of the accompanying drawings, wherein Figure 1 shows a rear elevation of the machine. Fig. 2 is a side elevation of Fig. 1. Fig. 3 is a section of part of the-machine, taken on line w y, Fig. 1. Figs. 4 and 5 represent back and side elevations, respectively, of one of the cutters detached and drawn to an enlarged scale. Fig. 6 isa section on linew m, Fig. 4-. Figs. 7 and 8 represent a segment of the rim of the fly-wheel, showing the Wiper or device which operates to remove the bur.

A represents a vertically-arranged plate plate A. On the extremity of the drivingshaft B at-the front of the machine is mounted a heavy fly-Wheel Z ,which conserves the power and applies it in the operation of the machine Specification of Letters Patent.

Application filed June 15, 1904:- Serial No. 212,666.

Patented Dec. 5, 1905.

I able speed in any other convenient manner.

This machine may be kept running continu ously, or otherwise, as may be preferred. On the shaft B, between the fly-wheel b and the front of-the supporting-plate A, is fitted an eccentric or cam b. j

To the-top of the'flplate A, at the front, is fixed another plate 0. This latter plate 0 may be fixed to the back plate A by means of bolts or the likepassed through the bolt-holes c from the front to the back of the machine. In the'front of the plate 0 are formed four radial dovetail groovesc, all of which meet in the front of a cylindrical hole 0 formed through both the front and back plates A C at the center. 7 In the dovetail grooves 0 four radial cutters D are arranged in such manner that they can advance toward or recede from the center of the cylindrical hole 0 formed in the plates A- C. The several cutters are of the same construction, and one is illustrated in detail in Figs. 4, 5, and 6 of the drawings. It is constructed in. its central portion 0? of dovetail section corresponding to the dovetail groove c in'the plate in which it slides, and its inner end is beveled off from the sides to the center and from the back to the front to form the pointed V-shaped cutter, as shown, which enters between adjacent webs or wings of the drill to cutoff the broken portion. The blade (2 of the cutter D is made somewhat thicker than the dovetail part 0?, so that it projects slightly beyond the level of the plate 0 at the front. The other and outer ends of the cutters D are formedwith a hole al for attaching them to their operating-levers. The several cutters are operated so that they move inward simultaneously and meet in the center. In Fig.1 the several cutters are shown in their innermost position. The means for operating the several cutters comprise a tappetlever E, which works on a pin or pivot c, fixed in the plate A. The arm 6' of the lever E is so arranged that it is engaged by the eccentric or camb on the main driving-shaft B, and thereby depressed. The other arm e is pivotally connected to an adjustable rod-e IOO 6 6 which operate the two horizontally-arranged cutters D. The levers e e are mounted on pins or pivots fixed to two lugs 0 formed on the front plate 0 at the bottom corners, the pins passing also through the back plate. One arm of each of the levers e e is connected to the rods 6 e and the other arms are connected to the outer ends of the two horizontal cutters D. The arms of these levers e e are formed with slots in which the pins 0, forming the connection between them and the cutters D, are located. This allows the arms of the levers e e to move in an arc of a circle, while the cutters move in a rectilinear path in either direction. The levers 0 6 are formed with bosses at the center, which bring the upper arms of the levers e 6 into line with the outer ends of the cutters D. The upper ends of the levers e e are preferably bifurcated, and the outer ends of the cutters D, carrying the pins e, fit into the bifurcations. The top vertical cutter D is operated by means of an adjustable rod e ,which is pivotally attached to one side of the arm 6 of the tappet-lever E. This rod 6 projects through a hole 0 formed through the plate O, which rod 6 projects above the top of the plate C, where it is pivotally attached to the outer end of the top vertical cutter D. The tappet-lever E is operated, by means of the eccentric or cam Z), to force the several cutters D inward to cut the drill, while the return stroke of the cutters is effected by means of a suitable spring F, fixed at its lower end and attached to the outer end of the arm 6 of the tappet-lever E. The several connecting-rods between the tappet-lever and the cutters D are made adjustable to allow of the rods being lengthened after the grinding of the cutters. The connecting-rods are shown made in two pieces formed with right and left hand screw-threads, over which adjusting-nuts f, formed with corresponding right and left hand threads are screwed, so that by turning the nuts f in one direction the rods are shortened, and by turning the nuts in the opposite direction the rods may be lengthened.

A rest f for the forward end of the drill F is provided fixed to the back of the plate A.

On the rim of the fiy-wheel b on the inside is fixed a wiper or projecting piece 6 This wiper b serves for taking off the bur or portion of the bit which is severed or partially severed by the several cutters D. This wiper b is fixed to the rim of the wheel in such a position that it passes over quite close to the front of the cutters D and just at the time that the cutters reach the end of their inward stroke.

In the operation of this machine the drill F is placed in the rest f and projected forward through the cylindrical hole c and between the cutters D sufficiently far for the cutters to remove the desired portion of the wings of the bit F. The four cutters D, moving inward simultaneously between the webs or wings of the drill F, sever or partially sever the piece to be removed, whereupon the wiper 6 completes the operation and detaches the same.

What I claim as my invention, and desire to protect by Letters Patent, is

1. Inapparatusforcuttingdrill-bits,aplate having radial guideways and a central aperture, cutters in said guideways adapted to move toward and away from the center of said aperture, means for reciprocating the cutters in their guideways, a driving-shaft, and means mounted on said shaft adapted to pass at intervals across the central aperture to remove the partially-severed portion of the drill held between the cutters.

2. In apparatus for cutting drill-bits, a plate having radial guideways and a central aperture, cutters in said guideways adapted to move toward and away from the center of said aperture, means for reciprocating the cutters in their guideways, a rotating member, and a device carried by said member for removing the partially-severed portion of the drill projecting beyond the cutters.

3. In apparatus for cutting drill-bits, a plate having radial guideways and a central aperture, cutters in said guideways adapted to move toward and away from the center of said aperture, means for reciprocating the cutters in their guideways, a shaft, a flywheel mounted on said shaft, and a wiper fixed to said fiy-wheel and adapted to pass across the central aperture of the plate.

4. In apparatus for cutting drill-bits, aplate having radial guideways and a central aperture, cutters in said guideways adapted to move toward and away from the center of said aperture, means for reciprocating the cutters in their guideways, a shaft, a lever mounted-independently of said shaft, means for connecting said lever with the several cutters, and means for actuating said lever to reciprocate the cutters.

5. In apparatus for cuttingdrill-bits, a plate having radial guideways and a central aperture. cutters in said guideways adapted to move toward and away from the center of said aperture, means for reciprocating the cutters in their guideways, a driving-shaft, a main lever mounted independently of said shaft, adjustable connecting means between said lever and the several cutters, means mounted on the driving-shaft for actuating the main lever, and means for returning the main lever to withdraw the cutters.

6. In apparatus for cutting drill-bits, in combination, amain plate, a second plate fixed thereto constructed with a central aperture and four guideways, cutters in said guideways, amain lever pivoted to the main plate, a connecting-rod between said lever and the lower vertical cutter, levers pivoted to the second plate and connected to the two hori- IIO zontal cutters, connecting-rods between said levers and the rod reciprocating the lower vertical cutters, a connecting-rod pivotally attached to the main lever and attached at its other end to the top vertical cutter, a driving-shaft, an eccentric on the driving-shaft engaging the main lever, a spring acting on said lever, a fly-wheel on the driving-shaft, and a wiper fixed on said fly-wheel and adapted 1 to pass across the central aperture to remove IO the partially-severed portion of the drill.

In witness whereof I have hereunto set, my handin the presence of two subscribing wit- HGSSGS.

JOSEPH ADOLPH GEORGE KIRSTEN. Witnesses:

CHAS. OVENDALE,

R. OVENDALE. 

